The Definition of the Subject:
Dress Fashion is any form of expression whose medi(um/a) (is/are) the material(s) worn on the body.
The Necessary Assumptions (NA):
NA1a. Dress Fashion has a function.
NA1b. Dress Fashion does not have an objective function.
NA1c. The function of Dress Fashion is specific to the
society employing the fashion.
NA2. There are characteristics that all societies share by virtue of being societies.
NA3. Dress Fashion has the potential to express all of the characteristics that all societies share.
NA4a. Subjective functionality can be derived from the character of a society.
NA4b. Subjective functionality can be derived from the common characteristics of all societies.
NA4c. Dress Fashion can have a subjective functionality that is common to all societies.
NA5a. Subjective functionality that is common to all societies is the most functional possible form of subjective functionality.
NA5b. Dress Fashion can have degrees of subjective functionality by the commonality of the characteristics that it expresses to the set of all societies.
NA6. The degree of subjective functionality of any given Dress Fashion within any given society is reflected immediately in the commonality (to all societies) of the characteristics that that given Dress Fashion expresses.
NA7. There is an inherently societal subjective functionality to Dress Fashion.
An Explication of the Necessary Assumptions:
To preface what I am about to write: Nothing in this section contradicts what has been stated in the Necessary Assumptions section; while the terms in this section will be used with less semantical precision than in the last, this is only to illuminate and make practical the tautological theory that has already been outlined. Any apparent logical failures in this section should be recognized as compromises of science for simplification, and it should be understood by all readers that Necessary Assumptions is where this case is proven.
The Theory of Dress Fashion states, in essence, that fashion is definite. The conclusion of its proof, at line NA7, states that fashion can be judged from an objective point of view, quantitatively, because while societies dictate their own fashions, all societies have the humanity that defines them in common. For example, while traditional Chinese men's fashion is stylistically very different from Savile Row tailoring, both tend to broaden the shoulders and chest of the person wearing them, while narrowing the hips. The male form is at its most exemplary when it is configured as top-heavy, which is agreed upon virtually everywhere in the world, so the efficacy of this dress configuration is a "fashion reality." This example also demonstrates lines NA5a.-b., which state that a fashion is more effective when it is more universally recognized. This assertion is made, as it can be seen in the proof, on the assumption that universally recognized fashions only receive the attention that they do because they are the most natural sorts of fashions, the sorts that will theoretically emerge in any society.
This theory is very loose, of course, and can actually be applied to the analysis any sort of "subjective functionality." It is very much like a Modal Ontological Argument; it does not make any absolute statements, but attempts to prove by the definition of its subject the subject's substance. There is a common misconception that fashion is random and capricious in nature, when in fact it is predictable, scientific and purposeful. Fashion is but human expression, and as the visual, language and musical arts have all demonstrated for thousands of years, people are very seldom original in their expressions.